Math 3349, Semester 2 2025

Welcome to Math 3349, Topics in Harmonic Analysis

In this course, we will cover some recent advances in harmonic analysis. I will post a list of topics each week, along with some references, as we go along.

Schedule:

Additional fun topics that we ran out of time for:
  • Reversed square functions, wave envelope estimates and related topics:
  • Larry Guth, Hong Wang and Ruixiang Zhang, A sharp square function estimate for the cone in R3, Annals Math 2020
    (See also Section 6 of Terry Tao and Ana Vargas GAFA 2000 for how an argument from [MSS92] deduces wave local smoothing from the Guth-Wang-Zhang square function estimate)
    Shengwen Gan and Shukun Wu, On local smoothing estimates for wave equations, arXiv 2502.05973
    Shengwen Gan, Dominique Maldague and Changkeun Oh, Sharp local smoothing estimates for curve averages, arXiv:2507.09696

  • Recent breakthrough on the Kakeya conjecture:
  • Hong Wang and Josh Zahl, Sticky Kakeya sets and the sticky Kakeya conjecture, arXiv 2210.09581, to appear in J Amer Math Soc
    Hong Wang and Josh Zahl, The Assouad dimension of Kakeya sets in R3, arXiv 2401.12337, to appear in Invent. Math.
    Hong Wang and Josh Zahl, Volume estimates for unions of convex sets, and the Kakeya set conjecture in three dimensions, arXiv 2502.17655
    Larry Guth, Introduction to the proof of the Kakeya conjecture, arXiv 2505.07695
    Larry Guth, Outline of the Wang-Zahl proof of the Kakeya conjecture in R3, arXiv 2508.05475

  • New perspectives on the restriction conjecture:
  • Hong Wang and Shukun Wu, Restriction estimates using decoupling theorems and two-ends Furstenberg inequalities, arXiv 2411.08871
This course concluded with every student submitting a final report on a topic of their choice. They often go beyond the material we covered in class. Here are some of the reports: